Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, and a turbine blade assembly for producing power. Combustors often operate at high temperatures that may exceed 2,500 degrees Fahrenheit. Typical turbine combustor configurations expose turbine vane and blade assemblies to these high temperatures. As a result, turbine vanes and blades must be made of materials capable of withstanding such high temperatures. In addition, turbine vanes and blades often contain cooling systems for prolonging the life of the vanes and blades and reducing the likelihood of failure as a result of excessive temperatures.
Typically, turbine vanes are formed from an elongated portion forming a vane having one end configured to be coupled to a vane carrier and an opposite end configured to be movably coupled to an inner endwall. The vane is ordinarily composed of a leading edge, a trailing edge, a suction side, and a pressure side. The inner aspects of most turbine vanes typically contain an intricate maze of cooling circuits forming a cooling system. The cooling circuits in the vanes receive cooling fluid, e.g., air from the compressor of the turbine engine, and pass the fluid through the ends of the vane adapted to be coupled to the vane carrier. The cooling circuits often include multiple flow paths that are designed to maintain all aspects of the turbine vane at a relatively uniform temperature. At least some of the fluid passing through these cooling circuits is exhausted through orifices in the leading edge, trailing edge, suction side, and pressure side of the vane.
The cooling system, as shown in FIG. 3, may include an impingement plate 3 with a plurality of impingement holes 4 for directing cooling fluids to impinge on the outer wall 6 forming a turbine airfoil. The impingement plate 3 may be offset from the outer wall 6 a conventional distance. The impingement plate 3 may be generally flat and reside in a single plane. In this configuration, the cross flow of cooling fluids often disrupts the impingement jets directed towards the outer wall, thereby negatively impacting the cooling function of the impingement jets. While advances have been made in the cooling systems in turbine vanes, a need still exists for a turbine vane having increased cooling efficiency for dissipating heat and passing a sufficient amount of cooling fluid through the vane.